Meet The Molecule That Can Supercharge Cancer-Killing Viruses

Since the turn of the millennium, the fight against cancer has seen significant progress in all areas of treatment. One of the most promising routes happens to be through a process known as oncolytic virotherapy, or simply OV. The term may be a mouthful but the process at its core is incredibly simple and effective.

Viruses need to live in cells to survive. But not every cell type will work, as most virus types prefer a particular cellular home. The common cold likes cells in the respiratory tract. Rabies prefers nerve cells. Norovirus only lives in the intestinal cells. When one of these viruses finds the right cell type, entry occurs using a lock-and-key approach (better known as receptor-ligand interaction). Once inside, the virus can go about its business.

Typically when a virus infects a cell, it's for the most part doomed. The process can take as little as a few hours depending on how fast the virus can multiply. The cell may put up a fight, but most of the time the end result is the same. In the process, the viruses held inside are released and are allowed to spread to other cells.

If the virus prefers a cancer cell, then infection can potentially destroy the tumour, leading to remission.

When this viral invasion occurs, it's usually an unwanted process as we end up getting sick. But in some cases, an infection can be good for us. If the virus prefers a cancer cell, then infection can potentially destroy the tumour, leading to remission. The concept has been around for over 60 years and has been sought for human cancer treatment for close to four decades.

Last year, OV took a huge step forward when the Federal Drug Administration in the United States officially approved a virus-based treatment for melanoma. The news sent waves of hope that the use of viruses may one day put an end to cancer.

Unfortunately, there is a catch to OV. It's still an invasion of the cell meaning the cancer cell will not take too kindly to the intrusion. While the cell may be doomed, depending on the strength of the defence, the virus may not get the job done. This has been one of the most troublesome hurdles for OV researchers and stands as a significant block in the progress of these treatments.

Now there may be a way forward. Last week, a team of group of Canadian researchers unveiled a new way to deal with cancer cell defences. Based on the results, the addition of a small molecule known as a sensitizer may be the key to ensuring OV success.

As the name implies, a sensitizer is a molecule with the ability to neutralize the fight within a cancer cell. Back in 2010, a method was developed to identify these chemicals. Not surprisingly, several potential candidates were found. But the process didn't stop there. In addition to natural molecules, synthetic analogues were developed and tested. The team tested dozens of different molecules in the hopes of finding one or several possible sensitizers. In total, they found 14. With these in hand, they then proceeded with a number of tests to prove these molecules were effective.

The tests followed a path similar to new antibiotics or other pharmaceutical agents. They first attempted to demonstrate the benefit of the molecule in OV using cell cultures. The process was relatively simple and did not incur any significant ethical issues.

If any of the molecules passed the test, the next stage was to use actual tumours collected from animals. This particular stage was considered to be the most important as it provided the right type of environment to determine if there was reason to move to living creatures.

From the 14, only four made the cut. They were then used in mice to determine whether they could be tolerated by the animals. This was an even harder test and as expected, three of the candidates did not impress. That left only one -- Number 28 -- to be taken to the ultimate step.

The test was simple. Take a mouse suffering from cancer and attempt OV along with candidate #28. But the importance of this experiment could not be understated. After all the years of testing and trials, this was the make or break moment.

It worked.

When the results came back, #28 had proven itself. The cancer progression had slowed and, more importantly, the mice lived longer than expected. When compared to OV treatment alone, the addition of #28 significantly improved the treatment. The milestone revealed just how the addition of a small molecule may one day make OV a true cancer cure.

Despite the good news, don't expect the sensitizers to be used for some time. There are still many hurdles ahead and the possibility of a failure is always present. But considering the importance of cancer in our everyday lives, this moment of success can foster even more hope that a cure may come thanks to our microbial terrestrial co-inhabitants.

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Lifestyle Risk Factors For Cancer

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It's no surprise smoking is the number one thing to avoid in order to prevent cancer. It's responsible for 30 per cent of all cancer deaths, and smoking can increase the risk of lung cancer, for example, by nine times.

Even if you don't smoke, you can be affected by those around you. People who are near smoking are 1.4 times more likely to get lung cancer than others.

Not having a healthy body weight (defined generally as a BMI of lower than 25) can increase your risk for a variety of cancers, including esophageal, uterine, liver, kidney, pancreatic, breast and colorectal cancer.

It's a big yes for veggies and fruit, as well as fibre, but red and processed meat is what you want to avoid. While eating lots of fibre, for example, can help reduce colorectal cancer risk, eating the meats can increase it.

Drinking any type of alcohol — at all — increases your risk for head/neck, esophageal, colorectal, breast and liver cancer (and potentially pancreatic too). You can decrease the risk by keeping your alcohol use confined to one drink a day for women, and two for men.

Getting at least 30 minutes of physical activity every day is what you should be aiming for. Otherwise, you're at risk for colorectal cancer and could be setting yourself up for lung, uterine and breast cancer.

We've heard about many ways in which sitting is bad for your health, but this could be the scariest one. Sitting too much (which is different from having physical activity) can increase your risk for colorectal, uterine, ovarian and prostate cancer.

Any type of tanning increases your risk for skin cancer — up to 64 per cent more for squamous cell carcinoma.

Hepatitis B and HPV both increase the risk for cancer, but there are vaccines that can help prevent them.

The presence of radon gas is associated with an increased risk for lung cancer — test your home to see if it's there.

This one is a double-edged sword. For women taking HRT post-menopause, it can increase the risk of breast, uterine and ovarian cancer, but may help decrease the risk for colorectal cancer. Birth control pills, meanwhile, have been associated with an increased risk for breast, cervical and liver cancer, but a decreased risk for uterine and ovarian cancer. If you're concerned, talk to your doctor about options.